Ebony Strain Research Articles

Pemanfaatan Drosophila Melanogaster Sebagai Organisme Model Untuk Mempelajari Pengaruh Faktor Lingkungan Terhadap Ekspresi Sifat Makhluk Hidup Pada Perkuliahan Genetika

The interaction between genetic and environmental factors in determining the characters of living organism is one of the main concepts in biology nowadays, and it becomes one of the main topic that students learn in genetics lecture. However, the observation result showed that regulation of gene expression in eukaryotes was considered to be a quite difficult topic for the students. The utilization of Drosophila melanogaster through practical activities can be used as an instructional media to help students understand the effect of environmental factors on the characters of living organism. This research aims to prove that through the crossbreeding of D. melanogaster for several generations, the effect of environmental factors on the characters of living organism can be observed. In this research, three strains of D. melanogaster were used to reveal the effect of dark environment on fecundity, which is one of the determinant factors of fitness in insects. The results showed that D. melanogaster treated in dark condition had lower fecundity than that in the control condition. The results of the comparison among the strains also showed that the strains of wild-type had higher fecundity than the white eyed color and ebony strains. The interaction between light conditions and generation and the interaction between light, strains, and generation also had an effect on the fecundity.

Physiological Stress Responses in Strains of the Gilthead Sea Bream (Sparus aurata)

In this study we examined the physiological responses of different strains of gilthead sea bream (Sparus aurata) to chronic and acute stress factors. Blood glucose levels, hematocrit, and lactate concentrations were examined in yearlings of different strains of gilthead sea bream subjected to different stress situations. In the first experiment, fish of the Ardag and ‘ebony’ strains were kept 45 days in moderate (35-45 kg/m3) or high (70-90 kg/m3) density. There were no significant effects on the blood glucose level but, at both densities, hematocrit was significantly higher in the Ardag strain (33.2±3.0% at moderate and 44.5±1.6% at high) than in the ebony strain (22.0±3.0% and 19.9±2.7%, respectively). The interaction of ‘strain’ and ‘crowding’ was highly significant, suggesting that hematocrit may respond differently in each strain to crowding. In the second experiment, we examined the effects of acute stress (handling without anesthesia) among four strains representing Mendelian mutations that affect body coloration in gilthead sea bream: ebony, ‘white’, ‘yellow’, and the normally pigmented Ardag. Significant variations in the glucose and lactate concentrations suggest that genotypes of gilthead sea bream may have heritable differences in their physiological responses to stress factors.

Differences in sperm competition and sperm competition avoidance in Drosophila melanogaster

When females mate multiply (polyandry), they create opportunities for competition among males for the fertilization of their eggs. Selection is expected to favour males capable of fathering more progeny under competition or males that can somehow induce females to refrain from multiply mating. Studies in Drosophila show that there is extensive variation in sperm competitive ability within populations and in adaptations to sperm competition between closely related species. Here we test differences in reproductive success when first or last to mate among Drosophila melanogaster males from strains of different geographical origin. Males from a Congo strain were weak sperm competitors when they were first or second to mate with females from an ebony strain. The weak sperm competitive ability of Congo males appears to be related to the quality of their sperm in female storage, but the effect was independent of female genotype. When Congo males mate first, they are capable of inducing higher female fidelity and egg laying than other males. However, egg-laying advantages are female dependant. These results suggest that males can evolve alternative adaptations to maximize their reproductive fitness, such as avoiding sperm competition through postcopulatory guarding (i.e. female fidelity) and inducing higher female reproductive investment (i.e. egg laying). Such adaptations are not necessarily transitive across competing males and females, which highlights the complexity of postmating reproductive adaptations in Drosophila.

Monitoring Tolerance to Insecticides in Boll Weevil Populations (Cole opera: Curculionidae) from Texas, Arkansas, Oklahoma, Mississippi, and Mexico

A glass vial technique was developed to estimate the toxicity of oregano phosphorus, carbonate, cyclocliene, and pyre throed insecticides to the boll weevil, Anthonomus grandis grandis Bohemian, and to monitor field populations for tolerance to such insecticides. In tests in which responses of the USDA Ebony strain boll weevils were compared With those collected in the field in the Bravos Valley, TX, in 1988, tolerance to oregano phosphorus, pyre throed, and carbonate insecticides was demonstrated. The usefulness of the glass vial technique for monitoring tolerance was confirmed in 1991 and 1992 by field data from Texas, Arkansas, Mississippi, Oklahoma, and Sonora, Mexico. These tests indicated tolerance to oregano phosphorus and pyre throed insecticides in several boll weevil populations. Tolerance monitoring may be a useful technique in the implementation of boll weevil eradication programs.

Studies on mutagen-sensitive strains of Drosophila melanogaster VIII. Further data on differences between Canton-S and ebony strains with respect to maternal effects for the X-ray induction of autosomal translocations and ring-X chromosome losses in mature spermatozoa

The influence of the maternal genotype ( Canton-S, proficient in the repair of X-ray-induced chromosome breaks and ebony, less proficient in this regard) on the recovery of X-ray-induced autosomal (II–III) translocations and ring-X chromosome losses in mature spermatozoa was studied. In the first series of experiments, males carrying appropriate markers on their second and third chromosomes were irradiated and mated to Canton-S or ebony females and the frequencies of II–III translocations were determined. In the second series of experiments, males carrying ring-X chromosomes were irradiated in N 2 or in O 2, mated to Canton-S or ebony females and the frequencies of XO males were determined; additionally, under similar gas-treatment and radiation conditions, the pattern of egg-mortality was also assessed. The data on translocations show that the yields are higher with ebony than with Canton-S females; these and earlier results on dominant lethals and sex-linked recessive lethals support the interpretation that the maternal repair system in the ebony strain is less proficient and more error-prone than that of the Canton-S strain. Those on the losses of ring-X chromosomes demonstrate that (i) the absolute yields of XO males are lower with ebony than with Canton-S females irrespective of whether the parental males are irradiated in N 2 or in O 2; (ii) the exposure-frequency relationships are all linear, but the slopes are higher when the males are irradiated in O 2 and are consistent with an oxygen-enhancement-ratio of about 1.5 and (iii) the relationships between the logarithm of egg-survival and XO male frequency are also linear, but the slopes for the O 2 groups are lower than those for the N 2 groups (slope ratios of 0.86–0.87). The finding that at given survival levels, the XO frequencies are lower in the O 2 than in the N 2 groups of both the Canton-S and ebony series viewed in the context of the mechanisms that have been postulated to explain the loss of ring-X chromosomes in irradiated mature spermatozoa permits the following interpretation for the observed results: (i) a higher proportion of potential XO zygotes is lost through dominant lethality in the O 2 groups than in the N 2 ones presumably because the chromosome breaks induced in O 2 are qualitatively different in the sense that they have higher probability to undergo reunions relative to restitution, compared with breaks induced under anoxia and (ii) this leads to lower than expected oxygen-enhancement ratios (i.e., expected on the basis of published data on sex-linked recessive lethals, another kind of genetic damage which shows a linear exposure-frequency relationship).

Studies on mutagen-sensitive strains of Drosophila melanogaster: V. Biochemical characterization of a strain ( ebony) that is UV- and X-ray sensitive and deficient in photorepair

We investigated larval sensitivity to UV and repair of UV- and X-ray-induced lesions in the DNA of the ebony strain compared to a wild-type strain ( Canton S). The ebony strain was previously characterized as being more sensitive to UV-induced killing of embryos than Canton S. Also the ebony strain is more sensitive to X-rays for induction of larval killing, dominant lethals and recessive lethals. In this paper it is demonstrated that (1) ebony larvae are more sensitive to killing by UV and less proficient in photoreactivation (PR) ability than Canton S larvae; (2) the ebony strain has a defect in PR repair of endonuclease-sensitive sites induced in the DNA of primary cell cultures by UV irradiation; (3) the ebony strain has a defect in the repair of single-stand breaks induced in the DNA by X-rays (again in primary cell cultures), at least easly on in the repair incubation. A rough localization of the UV sensitivity and the PR ability is presented and the possible relevance of the biochemical to the genetic results is discussed.

Role of beta-alanine in cuticular tanning, sclerotization, and temperature regulation in Drosophila melanogaster

Injection of 20 nl of 1.0 M beta-alanine, about the minimal amount needed to produce wild-type tanned phenomenocopies from newly eclosed mutant black Drosophila melanogaster, increases stiffness and puncture-resistance of the wing cuticle. Increasing the concentration of beta-alanine to 2.0 M increases puncture-resistance further. Injection of 1.0 M of the beta-alanine analogue beta-aminoisobutyric acid, does not induce tanning or puncture-resistance, nor does injection of 1.0 M dopamine. However, injection of 1.0 M beta-alanine and 1.0 M dopamine increases puncture-resistance more than an injection of 1.0 M beta-alanine, though not more than an injection of 2.0 M beta-alanine alone. Within 10 min after injection of [3- 3H]beta-alanine into newly eclosed normal flies, 3H becomes 8.7 times more concentrated in the cuticle than in an equal area of underlying epidermis. 3H is excluded from the epidermis or cuticle of ebony strains. Ebony strains show a deficiency of cuticular electron-absorbing material, and the cuticular lamellae show a tendency to separate from each other. Compaction of the chitinous lamellae is induced in alkali-detanned pupal sheaths by exposure to nascent quinones of N-acetyldopamine or N-beta-alanyldopamine. Glucosamine, but not N-acetylglucosamine, reacts with such quinones in tanning reactions. Under an infrared beam, black cuticular pigmentation induces more rapid heating of haemocoel fluids than does tan pigmentation. A theory of pigmentation and sclerotization relative to environmental adaptation is presented.

Studies on mutagen-sensitive strains of Drosophila melanogaster I. The enhanced X-ray sensitivity of a mutant strain ( ebony) which is UV-sensitive and also deficient in photorepair

Yegorova and colleagues (1978) showed that a mutant strain of Drosophila melanogaster (ebony) was more sensitive to UV-induced killing of embryos and also less proficient in photoreactivating (PR) ability than a wild-type ( Canton-S) strain and that the genes governing UV sensitivity and PR ability were different and presumably located on the autosomes. The experiments reported in the present paper were designed to compare the patterns of sensitivity of these 2 strains and their hybrids to X-irradiation. The sensitivity of the larvae to the killing effects of X-irradiation, and of male and female germ-cell stages to the X-ray induction of genetic damage was studied. It was found that the larvae of the ebony strain are more sensitive to X-ray-induced killing than those of the Canton-S strain. The frequencies of radiation-induced dominant lethals and sex-linked recessive lethals are higher in spermatozoa sampled from ebony males than in those of Canton-S males. In spermatozoa sampled from hybrid males, the yields of dominant lethals are no higher than in those sampled from Canton-S males and do not seem to depend on the origin of the X-chromosome. There are no statistically significant differences between the ebony and Canton-S strains in the sensitivity of their spermatozoa to the induction of autosomal translocations. Stage-7 oocytes sampled from ebony females are more sensitive to the X-ray induction of dominant lethality than are those from Canton-S females; oocytes sampled from hybrid females manifest a level of sensitivity that is significantly lower than that in either parental strain. The frequencies of X-chromosome losses induced in in this germ-cell stage are significantly lower in ebony than in Canton-S females at least at the exposure level of 3000 R at which 3 experiments were carried out. There are no measurable differences in the amount of dominant lethality induced in stage-14 oocytes of ebony, Canton-S and hybrid females. When X-irradiated Berlin-K males are mated to ebony or Canton-S females, the yields of dominant lethals are higher when ebony females are used, showing that there is a “maternal effect” for this kind of damage. Such a maternal effect is also found for sex-linked recessive lethals (irradiated Muller-5 males mated to ebony or Canton-S females). However, when irradiated ring-X-chromosome-carrying males are mated to ebony or Canton-S females, the frequencies of paternal sex-chromosome losses (scored as XO males) are lower when ebony females are used. These results have been interpreted on the assumption that the ebony strain is homozygous for recessive, autosomal genes that confer increased radiosensitivity and that the Canton-S strain carries the normal, wild-type alleles for these genes. The higher yields of dominant and recessive lethals in mature spermatozoa and of dominant lethals in stage-7 oocytes are a consequence of an enhanced sensitivity to the mutagenic (in particular, to the chromosome-breaking) effects of X-irradiation and/or of defective repair of radiation-induced genetic damage. The lower yield of XO males from irradiated stage-7 oocytes of ebony females is probably a consequence of a defect in the repair of chromosome-breakage effects, resulting in the conversion of potential X losses in females into dominant lethals. The “maternal effects” for dominant lethals, sex-linked recessive lethals and for the loss of ring-X chromosomes are assumed to have a common causal basis, namely, a defective repair of chromosome-breakage events in the females of the ebony strain.

The relationship between locomotor activity and sexual behaviour in ebony strains of Drosophila melanogaster

Male flies homozygous for the ebony 11 mutant allele suffer a severe visual impairment and consequently show poor mating success. However, ebony males show improved mating in darkness because they initiate courtship more quickly than in the light. They also exhibit a competitive superiority over wild-type males under darkened conditoons that correlates with the observed increase in the mutant's locomotor activity. Locomotor activity levels were subsequently shown to correlate with several indices of mating success under both dark and illuminated conditions. The evolutionary implications of this relationship between the two characters are discussed.

Circadian rhythmicity of tyrosine aminotransferase activity in larval and prepupal fat body ofDrosophila melanogaster

Abstract Drosophila melanogaster was reared under LD 12:12. Fat body was isolated in form of cells and cell groups from dissected larvae or prepupae by treatment with collagenase and hyaluronidase and subsequent centrifugation. Tyrosine aminotransferase of the fat body showed an extremely sharp pH dependence, with two narrow, well separable maxima at pH 5.6 and 6.0, possibly caused by different isoenzymes. Enzyme activity at pH 5.6 exhibited biphasic circadian rhythms in both wild‐type 3rd instar larvae and early prepupae. At pH 6.0, the rhythmicity was much weaker, perhaps even absent. In larvae from an ebony strain, at either pH the basal tyrosine aminotransferase activity was enhanced, and the rhythmicity was altered.

Daily oxygen uptake rhythms in male boll weevils, Anthonomus grandis boheman (Coleoptera: Curculionidae) of the ebony strain fed cotton squares (buds)

1. 1. Oxygen uptake was measured 8 times a day in 2–20-day old male and female boll weevils of the ebony strain. 2. 2. The insects were held under a 16 hr photophase or under continuous light. 3. 3. Time-of-day for low points and peaks of O 2 uptake were established. 4. 4. O 2 uptake was depressed when the light regime was switched from 16:8 L-D to continuous light. 5. 5. Presumptive evidence was obtained for the existence of an internal daily rhythm.

Oxygen uptake in male and female boll weevils, Anthonomus grandis boheman (Coleoptera: Curculionidae) of the ebony strain fed cotton squares (buds)

1. 1. Oxygen uptake was measured in 1- to 15-day-old male and female boll weevils of the ebony strain that were fed cotton squares (buds). 2. 2. O 2 uptake was found to range between 19.51 and 10.64 μl O 2/mg wet wt/hr for males and between 17.6 and 11.1 μl O 2/mg wet wt/hr for females. 3. 3. Peak O 2 uptake for males was recorded when they were 5 and 11–12 days old. 4. 4. Peak O 2 uptake for females was recorded when they were 6 and 12 days old.

Frequency-dependent mating success among mutant ebony ofDrosophila melanogaster

Measurements of the mating success of wild and ebony strains ofD. melanogaster with different degrees of competition have shown a frequency-dependent effect in both cases, but with a negative correlation for the wild and a positive correlation for the ebony strain.

Oxygen uptake in male and female boll weevils, Anthonomus Grandis boheman (Coleoptera: Curculionidae) of the ebony strain fed a laboratory diet

Abstract o 1. Oxygen uptake was measured in laboratory diet-fed 1- to 15-day old male and female boll weevils of the ebony strain. 2. O 2 uptake was found to be between 27·24 to 6·45 μl O 2 /mg wet wt per hr for males and between 26·37 and 5·64 μl O 2 /mg wet wt per hr for females. 3. Peak O 2 uptake for males was recorded when they were 4 and 12 days old. 4. Peak O 2 uptake for females was recorded when they were 6, 10, and 14 days old.

Baking and taste properties of bread made from hard wheat flour infested with species of Tribolium, Tenebrio, Trogoderma and Oryzaephilus

Experiments were undertaken to determine the effects of insect infestations on the baking and taste qualities of bread prepared from insect-infested flour. Bread prepared from flour previously infested with Oryzaephilus surinamensis (L), Tenebrio molitor L, Tribolium castaneum (Herbst), and Tribolium confusum (Duval) ebony strain, disclosed a variety of baking and taste quality changes after 1, 2, and 3 month infestation periods. Although bread made from flour infested with O. surinamensis and T. molitor revealed only minor changes in physical attributes, a ‘chemo-phenolic’ taste and odor was detected. Bread prepared from flour infested with T. castaneum and T. confusum showed many changes including a progressive darkening of the crumb, reduction in slice size, and a distinct offensive taste and odor which was intensified after longer infestation periods. The data support the hypothesis that quinone secretions adversely affect the taste qualities of bread made from Tribolium-infested flour, and this may be an important factor in lowering its baking qualities.

Aberrant segregation: a new case in Drosophila melanogaster.

Males from an ebony strain of Drosophila melanogaster show a consistent and deviant sex ratio in their progenies (53 to 57% females). The cause is a major gene on the X chromosome at approximately 48. Zygotic mortality is not the cause; therefore, a prezygotic mechanism is probably responsible. There is good evidence for a suppression effect (2 to 4%) by the autosomal component in the ebony strain. No effect was found for the two Y chromosomes tested.